Thanks that's interesting, mine will be D800 files, 36mp, I'm expecting it to wheeze... quite a bit, BUT it will be my travel companion, and I'm not expecting the performance to match my 2 year old home build desktop PC (benchmarks suggest PC twice as good as SP3 no surprises there really as not only is it the full blown i5 processor it's also got a dedicated graphics card), as long as it beats my old Dell laptop in to the shade I'll be happy, and my old laptop managed to import and render previews from a days shooting with the D800.... eventually
I'm lusting over a 810...but I really like the controls and feel of the bigger body.
Post when you have some results. LR import and rendering has always been a "Start it and go get a cup of coffee" operation.
Len